As part of my attempts to protect my computer from physical hacking by my client, see enter link description here, I am struggling with Grub2, specifically with how to prevent it from showing the boot menu.

I am trying to prevent the loading of the boot menu, even when the user hits SHIFT key.

1) I've tried disabling 30_os_prober. That doesn't affect the menu.

2) I've tried manually disabling the menu entries, but that just shows less entries and the one that is shown can be edited to provide shell login.

So, any ideas on how to disable the Grub2 boot menu? Any idea would be appriciated

3 Answers
3

Keep the timeout as it is: you may need it sooner or later. And if you boot the PC while keeping the SHIFT key pressed, it is possible that the zero timeout can be circumvented. Rather, password protect the relevant GRUB entries. You may also lock out the recovery modes.

I suppose this would work. The "correct" method would be to directly edit the existing line in /boot/grub/grub.cfg, or even better, change GRUB_TIMEOUT to 0 in /etc/default/grub and remake the config file.